Abstract
Willemite powders which have been prepared by solid state reaction were easy to intermixed impurities, and particle surfaces were demaged in the progress of crushing. The above defacts were easy to accompany non-crystallization for mechanochemical effects and luminescence efficiency was deteriorated. The goal of this study improve each of defacts, and synthesize high purity and fine Mn doped willemite powders by wet and hydrothermal methods without crushing progress. It has been experimentally verified that the single phase Zn1.98Mn0.02SiO4 willemite powders which prepared by hydrothermal synthes is at 220$^{\circ}C$ for 10 hours in 2N KOH solution. The products are like needle and composition is the same with starting composition.
